newlib/libc/xdr/xdr_reference.c

   1 /*
   2  * Copyright (c) 2009, Sun Microsystems, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  * - Redistributions of source code must retain the above copyright notice,
   8  *   this list of conditions and the following disclaimer.
   9  * - Redistributions in binary form must reproduce the above copyright notice,
  10  *   this list of conditions and the following disclaimer in the documentation
  11  *   and/or other materials provided with the distribution.
  12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
  13  *   contributors may be used to endorse or promote products derived
  14  *   from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /*
  30  * xdr_reference.c, Generic XDR routines impelmentation.
  31  *
  32  * Copyright (C) 1987, Sun Microsystems, Inc.
  33  *
  34  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
  35  * "pointers".  See xdr.h for more info on the interface to xdr.
  36  */
  37
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <errno.h>
  41
  42 #include <rpc/types.h>
  43 #include <rpc/xdr.h>
  44
  45 #include "xdr_private.h"
  46
  47 #define LASTUNSIGNED    ((u_int)0-1)
  48
  49 /*
  50  * XDR an indirect pointer
  51  * xdr_reference is for recursively translating a structure that is
  52  * referenced by a pointer inside the structure that is currently being
  53  * translated.  pp references a pointer to storage. If *pp is null
  54  * the  necessary storage is allocated.
  55  * size is the sizeof the referneced structure.
  56  * proc is the routine to handle the referenced structure.
  57  */
  58 bool_t
  59 xdr_reference (XDR * xdrs,
  60         caddr_t * pp,
  61         u_int size,
  62         xdrproc_t proc)
  63 {
  64   caddr_t loc = *pp;
  65   bool_t stat;
  66
  67   if (loc == NULL)
  68     switch (xdrs->x_op)
  69       {
  70       case XDR_FREE:
  71         return TRUE;
  72
  73       case XDR_DECODE:
  74         *pp = loc = (caddr_t) mem_alloc (size);
  75         if (loc == NULL)
  76           {
  77             xdr_warnx ("xdr_reference: out of memory");
  78             errno = ENOMEM;
  79             return FALSE;
  80           }
  81         memset (loc, 0, size);
  82         break;
  83
  84       case XDR_ENCODE:
  85         break;
  86       }
  87
  88   stat = (*proc) (xdrs, loc, LASTUNSIGNED);
  89
  90   if (xdrs->x_op == XDR_FREE)
  91     {
  92       mem_free (loc, size);
  93       *pp = NULL;
  94     }
  95   return stat;
  96 }
  97
  98
  99 /*
 100  * xdr_pointer():
 101  *
 102  * XDR a pointer to a possibly recursive data structure. This
 103  * differs with xdr_reference in that it can serialize/deserialiaze
 104  * trees correctly.
 105  *
 106  *  What's sent is actually a union:
 107  *
 108  *  union object_pointer switch (boolean b) {
 109  *  case TRUE: object_data data;
 110  *  case FALSE: void nothing;
 111  *  }
 112  *
 113  * > objpp: Pointer to the pointer to the object.
 114  * > obj_size: size of the object.
 115  * > xdr_obj: routine to XDR an object.
 116  *
 117  */
 118 bool_t
 119 xdr_pointer (XDR * xdrs,
 120         char **objpp,
 121         u_int obj_size,
 122         xdrproc_t xdr_obj)
 123 {
 124   bool_t more_data;
 125
 126   more_data = (*objpp != NULL);
 127   if (!xdr_bool (xdrs, &more_data))
 128     {
 129       return FALSE;
 130     }
 131   if (!more_data)
 132     {
 133       *objpp = NULL;
 134       return TRUE;
 135     }
 136   return (xdr_reference (xdrs, objpp, obj_size, xdr_obj));
 137 }